Function try_load_binary_rdata 

pub fn try_load_binary_rdata(
    data: &[u8],
    target_env: &Environment,
) -> Result<Option<Vec<Option<String>>>, RError>

Try to load a GNU R binary .RData file (RDX2 header + serialized pairlist).

Returns Ok(Some(loaded_names)) if the file is a valid binary .RData, Ok(None) if it’s not a recognized binary format (fall back to text).